Discovery of the Marine Triassic in the Lazhuglung area, Rutog County, northwestern Tibet, and establishment of the Wanquanhe Group

A sequence of carbonate rocks located at the Yaxier gully in the Lazhuglung area, Rutog County, Tibet, was previously assigned to the Yaxier Group and its age was incorrectly determined to be Devonian because of lacking of fossil evidence. Abundant Early Triassic bivalve and gastropod fossils were found in this sequence of strata in this study, thus providing evidence for dating the group. On that basis, this sequence of strata is named the Wanquanhe Group according to the definition of the lithostratigraphic unit.